---
categories: ['Devuan','Network','Service']
date: 2020-04-25T12:17:36+02:00
description: "To use on Devuan the OpenNTPD time synchronization client"
draft: false
tags: ['Devuan','OpenNTPD','ntp','client','temps']
title: "Devuan: use the OpenNTPD time synchronization client"
translationKey: "devuan-openntpd-client"
---

## Description

**OpenNTPD** is a service that can be used to synchronize the system clock
to the time servers using the {{< abbr NTP "Network Time Protocol" >}}.

**OpenNTPD** is a part the OpenBSD base system. It was ported to others OSes, 
as Devuan.

## Installation

With the `apt` tool: `apt install openntpd`

## Configuration

* The file config is: `/etc/opennptd/ntpd.conf`

By default, it runs without no needed modification.

{{< file "openntpd-ntpd.conf-1.14" cfg "/etc/opennptd/ntpd.conf" >}}

**Explanations** 

About options: 

* `server`: to target on time server, in particular. 
* `servers`: to targer a pool of time servers - *prefer this*
* `sensor`: to use local timedelta sensor

## Utilisation

### Checks

To check the file config, use the option `-n`, as-is: <br>
`# openntpd -n` <br>
`configuration OK`

If not good, you need to review the file config. 

---

`ntpctl` is the tool to control the time informations. 

* the option `-s all` - or `-sa` - is to display availables informations.

{{< code "openntpd-ntpctl-sa-example" shell >}}

{{< note info >}} 
To known all usefull options, please see the manpage  {{< anchor ntpctl manpages >}}.
{{</note>}}

### Service

The service name is **openntpd**, to manage with the `service`.

`service openntpd command` 

* `command` is one of possibles actions on a service, as `start`, 
	`stop`, `restart`.

## Troubleshooting

It can happen at startup that there is a time lag. Using the option `-s` 
solve: 

{{< code "sys-devuan-openntpd-option-s" shell >}}

### Constraint

It seems the constraint option is not available!

{{< note info >}}
This option `constraint` ensures that time queries are made on the
 protocol {{< abbr HTTPS "HyperText Transfert Protocole Secure" >}}, 
via {{< abbr TLS "Transport Layer Security" >}}.
{{</note>}}

### peer not valid

You have this message: 

{{< code "openntpd-ntpctl-sa-peer-not-valid-example" shell >}}

Wait a little for the ntp queries to be returned. <br>
Normally at the next query, this should no longer be the case. 

Otherwise, check that the NTP servers registered in the file config
 are well written, reachable and functional.  

## Documentation

The NTP protocol is defined in:

* version **3** by {{< anchor "RFC 1305" "rfc 1305" >}}
* version **4** by {{< anchor "RFC 5905" "rfc 5905" >}}

{{< rfcdoc 1305 >}}
{{< rfcdoc 5905 >}}

### Manpages

Please, read the manpages: 

* {{< man ntpd 8 >}}, {{< man ntpd.conf 5 >}}, {{< man ntpctl 8 >}}

---